The present invention relates to a method of producing an alloy, and to an apparatus for practicing said method; and more particularly relates to a method of producing an alloy of two materials such as metals or mixtures thereof which have substantially different melting points, and to an apparatus for practicing such a method.
It should be understood that, although henceforward in the present specification the present invention will be described in terms of manufacturing an alloy of two metals, and the terms "the first metal" and "the second metal" will be utilized hereinafter freely, this is not intended to restrict the scope of the present invention to less than that of the claims appended to this specification: in particular, the two materials an alloyed mixture of which is formed according to the method of the present invention by the apparatus of the present invention can be elemental metals as a particular case and some of the particular exemplary embodiments which will be described later relate to such cases, but this is not an essential feature of the present invention, and notwithstanding the language utilized hereinafter for purposes of conciseness of description each of these constituents may in fact alternatively be a metal-like element, an alloy of metals, or an alloy of metals and/or metal-like elements. All such variations are to be understood as coming within the scope of the present invention.
In the prior art, then, for making an alloy of a first and a second metal, the following methods have been practiced.
First, and most simply, both the first and the second metal have been melted, and then the molten first and second metals have been mixed together and stirred together so as to be intimately compounded, the resultant mixture then being cooled and solidified. Secondly, as an alternative, the first metal has been melted, and the second metal has been added thereto in powder form or the like and stirred thereinto. These methods suffer from the disadvantages that, if both the first and the second metal must be melted, a large amount of heat energy is required, and also that if the specific gravity difference between the first and the second metal is large it is very difficult to secure good and uniform mixing of the first and second metals in order to obtain an alloy which has a uniform composition. Further, many metals in the molten state are subject to severe attack by and combination with the gases in the atmosphere, and if either of the first and the second metal includes such a metal or metals then modification of the working atmosphere, such as establishment of a vacuum, is required. This can entail high cost.
Further, in production of an alloy in which at least one of the component metals has a high melting point, it has been practiced to make the component metals into powder, to mix these metallic powders, and then by such a process as sintering at high temperature to diffuse these component elements into one another to form an alloy. However, this method of producing an alloy is also not entirely satisfactory, for the following reasons. First, it is difficult to completely eliminate air or other gas which is initially present between the particles of the combination powder, and accordingly it is difficult to prevent some of this gas from remaining within the alloy after the sintering and diffusion process. This can lead to voids within the produced alloy, which is not of 100% density, which can severely deteriorate the strength and other mechanical properties thereof. Second, since these sintering and diffusion processes involve heating at high temperature and modification of atmosphere, again the production cost can be rather high.